Front Cover 1
Stem Cell Biology and Tissue Engineering in Dental Sciences 4
Copyright 5
Contents 6
List of Contributors 24
Foreword 32
Chapter 1: An Introduction to Stem Cell Biology and Tissue Engineering 34
1.1. Introduction 34
1.2. The emergence of Tissue Engineering and regenerative medicine 35
1.3. Research themes underlying Tissue Engineering technology 37
1.3.1. Cells 37
1.3.2. Biomaterial Scaffolds 39
1.3.3. Tissue-Inducing Factors 40
1.3.4. Devices and Systems 41
1.4. Stem cell-based therapy 41
1.4.1. Pure Stem Cell Therapy 42
1.4.2. Scaffold-Based Stem Cell Therapy 42
1.5. Translational Tissue Engineering 43
1.6. Conclusion 44
References 44
Part I: Developmental Biology: A Blueprint for Tissue Engineering 48
Chapter 2: Developmentally Inspired Regenerative Organ Engineering: Tooth as a Model 50
2.1. Introduction 50
2.2. Understanding generation for regeneration strategies: a tooth model 50
2.3. Epithelial-mesenchymal interactions during odontogenesis 51
2.4. ECM and mechanical forces as regulators of organogenesis 53
2.5. Engineering approaches for tooth organ regeneration 53
2.6. Conclusion 55
References 56
Chapter 3: Extracellular Matrix Molecules 58
3.1. Introduction 58
3.1.1. Overview 58
3.1.2. Extracellular Matrix Proteins 59
3.1.3. Crosslinking 60
3.2. Collagens 60
3.2.1. Collagen Biosynthesis and Processing 61
3.2.2. Fibril-Forming Collagens 61
3.2.2.1. Biomineralization 63
3.2.3. Fibril-Associated Collagens (FACITs) 63
3.2.4. Network-Forming Collagens 63
3.2.5. Anchoring Fibrils 64
3.2.6. Other Collagens 64
3.2.7. Collagenopathies 64
3.2.7.1. Osteogenesis Imperfecta (OI) 64
3.2.7.2. Ehlers-Danlos Syndrome 66
3.2.7.3. Skeletal Dysplasias and Chondrodysplasias 66
3.2.7.4. Other Collagenopathies 66
3.3. Glycoproteins 67
3.3.1. Fibronectin 67
3.3.2. Fibrillins and Latent TGF-ß-Binding Proteins (LTBPs) 67
3.3.2.1. Structural and Functional Properties of Fibrillins and LTBPs 67
3.3.2.2. Fibrillinopathies 68
3.3.3. Fibulins 69
3.3.4. Other Glycoproteins 69
3.3.4.1. Tenascin 69
3.3.4.2. The Small Integrin-Binding Ligand N-Linked Glycoproteins (SIBLINGs) 69
3.3.4.3. Thrombospondins 70
3.4. Elastin and Elastic Fibers 70
3.4.1. Elastic Fiber Assembly 70
3.4.2. Elastin-Associated Pathologies 70
3.5. Basement Membranes 70
3.5.1. Laminins 71
3.5.2. Collagen Type IV 71
3.5.3. Basement Membrane Proteoglycans 71
3.5.4. Basement Membrane-Associated Pathologies 72
3.6. Proteoglycans and Glycosaminoglycans 73
3.6.1. Glycosaminoglycans 73
3.6.2. Proteoglycans 74
3.6.2.1. Cell Surface Proteoglycans 74
3.6.2.2. Modular Proteoglycans 74
3.6.2.3. Small Leucine Rich Proteoglycans (SLRPs) 74
3.7. Concluding Remarks 75
Acknowledgments 75
Abbreviations 75
References 76
Chapter 4: Cell-Matrix Interactions and Signal Transduction 80
4.1. Introduction 80
4.1.1. The First Evidence that Matrices Change Cell Behavior 80
4.1.2. Integrin and Non-Integrin Receptor Discovery 82
4.2. Receptors 83
4.2.1. Integrins: Mediators of Cell-Matrix Interactions 83
4.2.1.1. Integrin a Subunits 83
4.2.1.2. Integrin ß Subunits 83
4.2.2. Non-Integrin Receptors for ECM Molecules 84
4.2.2.1. Syndecans 84
4.2.2.2. Laminin Receptor 84
4.2.2.3. Discoidin Domain Receptors 84
4.2.2.4. Leukocyte-Associated Immunoglobulin-Like Receptor-1 84
4.2.2.5. Glycoprotein VI 84
4.3. Cell-Matrix Signaling Transduction 85
4.3.1. Integrin-Mediated Cell-Matrix Signal Transduction 85
4.3.2. Crosstalk Between Integrin and Other Surface Receptor Pathways 86
4.4. Control Over Cell-Matrix Interactions 87
4.4.1. Control over Cell-Matrix Interaction Through Matrix Mechanical Forces 87
4.4.2. Control over Cell-Matrix Interaction Through Matrix Topography 88
4.4.3. Regulation of ECM Remodeling by Cell-Matrix Interactions 89
4.5. Cell-Matrix Interactions and Signal Transductions Viewed in Three Dimensions 90
4.6. Conclusion 91
References 91
Chapter 5: Cell Adhesion and Movement 94
5.1. Overview 94
5.2. Cell Adhesions 94
5.2.1. Cell Adhesions to Matrix 94
5.2.1.1. Focal Complexes 95
5.2.1.2. Focal Adhesions 95
5.2.1.3. Fibrillar Adhesions 96
5.2.1.4. Podosomes 96
5.2.1.5. Invadopodia 96
5.2.1.6. Non-Integrin-Mediated Adhesions to Matrix 96
5.2.1.7. Adhesions in Three-Dimensional (3D) Spaces 96
5.2.2. Cell Adhesions to Other Cells 96
5.2.2.1. Adherens Junctions 97
5.2.2.2. Tight Junctions 98
5.2.2.3. Gap Junctions 98
5.2.2.4. Desmosomes 98
5.2.2.5. Hemidesmosomes 98
5.3. Cell Movements 98
5.3.1. Single Cell Migration 98
5.3.1.1. Chemotaxis 99
5.3.1.2. Haptotaxis 99
5.3.1.3. Durotaxis 99
5.3.2. Collective Migration 100
5.3.2.1. Sheet Migration 100
5.3.2.2. Cell-Cell Contact-Guided Migration 101
5.3.2.3. Tailgating Migration 101
5.4. Conclusion 101
Abbreviations 101
References 101
Part II: In Vitro Regulation of Cell Behaviour and Tissue Development 106
Chapter 6: Genetic Manipulation Via Gene Transfer 108
6.1. Introduction to Basic Biology of Gene Transfer 108
6.2. Gene Transfer Methodologies 109
6.2.1. Specific Gene Delivery Approaches 110
6.2.1.1. Viral Vectors 110
6.2.1.2. Nanoparticles 110
6.2.1.3. Naked DNA Entry Through Membrane Disruption 110
6.2.2. Gene Delivery Considerations 111
6.2.2.1. Endosomal Escape Mediated by Viral Vectors and Nanoparticles 111
6.2.2.2. Cytoplasmic Trafficking of Genetic Payload 111
6.2.2.3. Nuclear Import and Fate of Genetic Payload 111
6.2.2.4. Matching Vector and Target 112
6.3. Host Response to Gene Transfer 112
6.3.1. Classical Anti-Viral Response to Viral-Mediated Gene Transfer 112
6.3.2. Intracellular Response to Gene Transfer 113
6.3.3. Implications for Human Gene Therapy 113
6.4. Examples of Successful Genetic Manipulation via in Vivo Gene Transfer 113
6.4.1. Pre-Clinical Ex Vivo and In Vivo Gene Transfer Strategies 113
6.4.2. Future Potential Approaches to Gene Therapy Currently at Earlier Stages of Development 114
6.4.3. Limitations of Pre-Clinical Studies 115
6.5. Pathway to Clinical Implementation of Therapeutic Gene Transfer 115
6.6. Conclusion 116
References 116
Chapter 7: Growth Factors: Biochemical Signals for Tissue Engineering 118
7.1. Growth Factors and Signal Transduction 118
7.2. Growth Factors and Signaling in Tissue Development 119
7.2.1. Tissue Interactions in Tooth Development 119
7.2.2. Signaling Networks in Dental Epithelium 120
7.2.3. Signaling Networks in Dental Mesenchyme 123
7.2.4. Signaling Networks Involved in Determining Tooth Number 123
7.3. Overview of the Signaling Pathways 124
7.3.1. BMP Signaling Pathway 124
7.3.2. FGF Signaling Pathway 125
7.3.3. Hedgehog Pathway 125
7.3.4. Wnt Signaling Pathway 126
7.4. Conclusion 127
Acknowledgments 127
References 127
Chapter 8: Mechanical and Physical Regulation of Cell Behavior 132
8.1. Introduction 132
8.1.1. Key Concepts 133
8.2. Tensile Stretch Regulation of Cell Behavior 133
8.2.1. Stretching in Two-Dimensional Environments 134
8.2.2. Stretching in Three-Dimensional Environments 136
8.3. Compression/Pressurization Regulation of Cell Behavior 137
8.4. Fluid Flow Regulation of Cell Behavior 140
8.4.1. Two-Dimensional Macro Fluid Flow 140
8.4.2. Three-Dimensional Macro Fluid Flow 141
8.4.3. Microfluidics 142
8.5. Alternative Stimulation Techniques 143
8.6. Synergy of Physical Cues and Other Factors 144
8.7. Conclusion 144
Abbreviations 145
References 145
Chapter 9: Bioreactor Technology for Engineering Craniofacial Tissues 150
9.1. Introduction: Rationale for Using Bioreactors in Stem Cell-Based Tissue Engineering 150
9.1.1. Key Concepts 151
9.2. Principles of Bioreactor Design 151
9.2.1. Environmental Control 151
9.2.2. Mass Transport 152
9.2.3. Sterility 152
9.2.4. Cell Seeding 152
9.2.5. Common Bioreactor Designs 153
9.2.5.1. Continuous Stirred-Tank Bioreactors 153
9.2.5.2. Rotating Wall Vessel Bioreactors 153
9.2.5.3. Perfusion Bioreactors 153
9.2.5.4. Customized Bioreactor Designs 153
9.3. Case Studies 154
9.3.1. Perfusion Bioreactors for Engineering Anatomically Shaped TMJ Bone Grafts 154
9.3.2. Bioreactors for Meniscus Tissue Engineering 155
9.3.2.1. Rotating Wall Bioreactor for TMJ Disc 156
9.3.2.2. Tension-Compression Bioreactor for Meniscus Engineering 157
9.3.3. Bioreactors for Engineering Aligned Periodontal Ligament Tissues 157
9.4. Future Perspectives 159
9.4.1. Bioreactors for Composite Tissues 159
9.4.2. Tissue Engineering Bioreactors for Clinical Application 160
9.5. Conclusion 161
References 161
Part III: Biomaterials in Tissue Engineering 164
Chapter 10: Considerations on Designing Scaffold for Tissue Engineering 166
10.1. Introduction to Scaffold-Based Tissue Engineering 166
10.2. Importance of Scaffolds in Tissue Engineering and Their Role 167
10.3. Scaffold Designing Criteria 168
10.3.1. Scaffold Properties to Consider 168
10.3.2. Selection of Biomaterials 168
10.4. Cell Matrix (scaffold) Interactions 173
10.5. Fabrication Techniques for Three-Dimensional Scaffolds 174
10.5.1. Conventional Methods 174
10.5.1.1. Solvent-Casting Particulate Leaching 174
10.5.1.2. Gas Foaming 175
10.5.1.3. Fiber Meshes/Fiber Bonding 175
10.5.1.4. Phase Separation 175
10.5.1.5. Melt Molding 175
10.5.1.6. Emulsion Freeze Drying 175
10.5.1.7. Solution Casting 175
10.5.2. Solid Free Fabrication Methods 175
10.5.2.1. Stereolithography and Selective Laser Sintering 175
10.5.2.2. Three-Dimensional Printing 176
10.5.2.3. Microsyringe Deposition 176
10.5.3. Microfabrication Techniques Based on Physical Properties 176
10.5.3.1. Microphase Separation 176
10.5.3.2. Self-Assembly 176
10.5.4. Hybrid Scaffolds 177
10.5.5. Nanofabricated Scaffolds 177
10.5.5.1. Electrospinning 177
10.5.5.2. Colloidal Adsorption 178
10.6. Conclusion and Future Trends 178
Abbreviations 179
References 179
Chapter 11: Polymeric Biomaterials as Tissue Scaffolds 182
11.1. Introduction 182
11.1.1. Natural Polymers 182
11.1.2. Synthetic Polymers 183
11.2. Non-Biodegradable Synthetic Biomaterials 183
11.2.1. Ceramics and Bioactive Glass 183
11.3. Degradable Synthetic Biomaterials 183
11.3.1. Polyesters 183
11.3.1.1. Poly(Glycolide) 184
11.3.1.2. Poly(Lactide) 184
11.3.1.3. Poly(Caprolactone) 185
11.3.1.4. Poly(Trimethylene Carbonate) 185
11.3.2. Poly (Ether-Ester) 185
11.3.2.1. Poly(Dioxanone) 185
11.3.3. Poly(Ethylene Glycol) 186
11.4. Bone Tissue Engineering in the Oral Cavity 186
11.4.1. Biomaterials for Bone Tissue Engineering 186
11.5. Tissue Engineering of the Gingiva and Other Soft Tissues 187
11.5.1. Epidermal Replacements 187
11.5.2. Dermal Replacements 188
11.6. Dental Nerve Injuries 189
11.6.1. Scaffolds for Nerve Tissue Engineering 189
11.7. Conclusion 191
Abbreviations 191
References 191
Chapter 12: Ceramic Biomaterials as Tissue Scaffolds 196
12.1. Introduction to Bioceramic Scaffolds 196
12.2. Calcium Phosphates 197
12.2.1. Preparation of Hydroxyapatite 198
12.2.2. Wet Methods 198
12.2.3. Dry Methods 199
12.2.4. Hydrothermal Methods 199
12.2.5. Biphasic Ceramics 199
12.3. Bioactive Glasses and Glass-Ceramics 199
12.3.1. Composition of Bioactive Glasses and Glass-Ceramics 199
12.3.2. Fabrication of Bioactive Glass and Glass-Ceramics 201
12.3.3. Properties of Bioactive Glass and Glass-Ceramics 201
12.3.4. Surface Reaction and Tissue Bonding 201
12.3.5. Clinical Applications of Bioactive Glass and Glass-Ceramics 202
12.4. Processing Methods for Scaffold Production 202
12.4.1. Foam Templating Methods 202
12.4.2. Leaching and Burnout Methods 203
12.4.3. Additive Layer Manufacturing 203
12.5. Naturally-Derived Implant Materials 203
12.5.1. Deproteinized Bone 203
12.5.2. Thermally-Treated Bovine Bone 204
12.6. Interaction of Bioceramics with Cells 204
12.7. Summary 204
References 204
Chapter 13: Gradient Biomaterials as Tissue Scaffolds 208
13.1. Introduction 208
13.2. The Concept of Gradient Biomaterials 211
13.2.1. Physical Gradients 211
13.2.2. Gradients of Surface Properties 211
13.2.3. Pore Size/Porosity Gradients 212
13.2.4. Substrate Stiffness Gradients 213
13.3. Chemical/Biological Gradients 214
13.3.1. Immobilized Factor Gradients 214
13.3.2. Soluble Gradients 215
13.4. Conclusion 216
Abbreviations 216
References 216
Chapter 14: Surface Functionalization of Biomaterials 220
14.1. Introduction 220
14.2. Responses to Biomaterial Implantation 220
14.3. Surface Modification Techniques 222
14.3.1. Chemically Based Methods 223
14.3.1.1. Surface Hydrolysis 223
14.3.1.2. Surface Oxidation 224
14.3.1.3. Aminolysis 224
14.3.1.4. Plasma Treatment 225
14.3.1.5. Surface Grafting Strategies 225
14.3.2. Physically Based Methods 226
14.3.2.1. Surface Adsorption 226
14.3.2.2. Entrapment 226
14.3.2.3. Self-Assembled Monolayers 226
14.3.2.4. Electrostatic Layer-by-Layer Deposition 227
14.4. Anti-Fouling Surface Modification Strategies 228
14.4.1. Poly(Ethylene Glycol) (PEG) 228
14.4.2. Polysaccharides 229
14.4.3. Zwitterionic Polymers 230
14.5. Biomimetic Surface Modification Strategies 230
14.5.1. Proteins and Peptides 230
14.5.2. Surface Biomineralization 231
14.6. Bioactive Surface Modification Strategies 232
14.7. Hybrid Strategies 232
14.8. Challenges in Three-Dimensional (3D) Surface Modification 233
Abbreviations 233
References 233
Chapter 15: Microfabrication and Nanofabrication Techniques 240
15.1. Introduction 240
15.2. Delivery of Soluble Factors Using Micro- and Nanofabrication Techniques 241
15.3. Microfabrication and Nanofabrication of Scaffolds 242
15.3.1. Vascular Network and Nerve Regeneration within Scaffolds 243
15.4. Micro- and Nanofabrication Techniques for Direct Fabrication of Cell-Laden Constructs 247
15.5. Elucidation of Stem Cell Biology Using Micro- and Nanofabrication Techniques 247
15.6. Concluding Remarks and Future Directions 248
Acknowledgments 249
Abbreviations 249
References 249
Chapter 16: Nanobiomaterials for Tissue Engineering Applications 254
16.1. Introduction 254
16.2. Two-Dimensional Nanotechnology for Dental Application 255
16.2.1. Nanolithography 255
16.2.1.1. Hot Embossing Imprint Lithography 256
16.2.2. Chemical Etching 256
16.2.3. Grit Blasting 257
16.3. Three-Dimensional Nanotechnology for Dental Applications 258
16.3.1. Nanohydroxyapatite 258
16.3.2. Nanofibers 260
16.3.2.1. Electrospinning 260
16.3.2.2. Self-Assembled Nanomaterials 260
16.3.3. Carbon Nanotubes 261
16.4. Nanoparticles for Drug Delivery 262
16.4.1. Nanobiomaterial and Cellular Interactions 263
16.5. Conclusions 264
Acronyms and Abbreviations 264
References 264
Part IV: Oral and Craniofacial Stem Cells for Tissue Engineering 268
Chapter 17: The Basic Principles of Stem Cells 270
17.1. Introduction to Stem Cells 270
17.2. A Brief History of Stem Cell Research 271
17.3. Characterization of Stem Cells 271
17.3.1. Origin of Stem Cells 271
17.4. Biological Properties of Stem Cells 272
17.4.1. Self-Renewal 272
17.4.2. Extensive Proliferative Capacity 273
17.4.3. Differentiation Potential 274
17.4.4. Stem Cell Plasticity 275
17.4.5. Stem Cell Resistance and Quiescence 276
17.5. Stem Cell Niche 277
17.6. Conclusion 278
Acknowledgment 278
Abbreviations 278
References 279
Chapter 18: Embryonic Versus Adult Stem Cells 282
18.1. Introduction 282
18.2. Embryonic Stem Cells 282
18.2.1. Definition 282
18.2.2. Origin and Derivation 282
18.2.3. Differentiation of ESCs In Vivo Versus In Vitro 283
18.2.4. Validation of Stem Cell Populations 283
18.2.4.1. Stem Cell Markers 283
18.2.4.2. Defining Characteristics of ESCs 283
18.2.4.2.1. Embryoid Body (EB) and Teratoma Formation in Mice 283
18.2.4.2.2. Derivation of Chimeric Offspring In Vivo and Tetraploid Complementation 283
18.2.5. Signaling Regulation in ESCs 283
18.2.6. ESC Culture Dependence on Growth Factors 284
18.2.7. iPS Cells 284
18.2.8. Applications of ESCs 285
18.3. Adult Stem Cells 285
18.3.1. Definition 285
18.3.2. Types of Adult Stem Cells and Their Markers 285
18.3.2.1. Hematopoietic Stem Cells 285
18.3.2.2. Mesenchymal Stem Cells 286
18.3.2.3. Intestinal Stem Cells 287
18.3.2.4. Neuronal Stem Cells 288
18.3.2.5. Stem Cells of the Epidermis and Hair Follicle 288
18.3.2.5.1. Epidermal Stem Cells 288
18.3.2.5.2. Hair Follicle Stem Cells 289
18.3.2.5.3. Sebaceous Gland Stem Cells 290
18.3.2.5.4. Dermal Papilla 290
18.3.2.6. Other Adult Stem Cell Populations 290
18.4. Applications of Adult Stem Cells 291
18.5. Conclusion 291
Abbreviations 292
References 292
Chapter 19: Dental Epithelial Stem 296
19.1. Introduction 296
19.2. Differentiation of Epithelial Cell Lineages in the Developing Tooth 296
19.3. Epithelial Stem Cells in the Continuously Growing Mouse Incisor 297
19.4. Epithelial Stem and Progenitor Cells for Tooth Replacement 300
19.5. Dental Lamina as the Origin of Epithelial Cells in Teeth 301
19.6. Conclusion 301
Abbreviations 302
References 302
Chapter 20: Dental Follicle Stem Cells 304
20.1. Introduction 304
20.2. Dental Follicle Cell Culture 305
20.3. Stem Cells of the Human Dental Follicle 306
20.3.1. Isolation of Multipotent Cells from the Coronal Human DF 306
20.3.1.1. The Migration Capacity of DFCs 306
20.3.1.2. The Regulation of the Differentiation of DFCs 306
20.3.2. The Periapical Follicle Stem Cells (PAFSCs) 307
20.3.3. Follicle-Derived Embryonic Neural Crest Stem Cells (FENCSCs) 308
20.4. Dental Follicle Cells for Regenerative Dentistry 308
20.5. Conclusion 309
References 309
Chapter 21: Dental Pulp Stem Cells 312
21.1. Introduction 312
21.2. Human Dental Pulp-Derived Mesenchymal Stem-Like Cells 313
21.2.1. Identification 313
21.2.2. Characterization and Origin 313
21.2.3. Growth Potential 315
21.3. Properties of Stem Cell Populations from Dental Pulp Tissue 315
21.3.1. Regenerative Potential of Mineralized Tissues 315
21.3.2. Immunomodulatory Properties 317
21.3.3. Neural Tissue Regenerative Potential 317
21.3.4. Dental Pulp-Derived Inducible Pluripotent Stem Cells 318
21.4. Conclusion 318
References 318
Chapter 22: Periodontal Ligament Stem Cells 324
22.1. Introduction 324
22.2. Periodontal Ligament Stem Cells (PDLSCs) 324
22.2.1. Identification 324
22.2.2. Characterization and Origin 324
22.2.3. Growth Potential 325
22.3. Induced Pluripotent Stem Cells from Periodontal Ligaments 325
22.3.1. Regaining Pluripotent Stem Cell Properties 325
22.3.2. Dental Originated Pluripotent Stem Cells 326
22.3.3. Application of iPSCs to Dental Regeneration 326
22.4. Epithelial Stem Cells from Periodontal Ligament 326
22.4.1. Hertwig’s Epithelial Root Sheath and the Epithelial Cell Rests of Malassez (HERS/ERM) 326
22.4.2. Epithelial Stem Cells in Periodontal Ligaments and ERM 326
22.5. Clinical Regeneration Properties and Potential of PDLSCs 327
22.5.1. Clinical Regeneration of Periodontium 327
22.5.2. Xeno-Free In Vitro Culture 327
22.5.3. Interaction with Multiple Tissue Structure 328
Abbreviations 328
References 328
Chapter 23: Oral Mucosal Progenitor Cells 330
23.1. Introduction 330
23.1.1. The Oral Mucosa 330
23.1.2. Distinct Tissue Repair Properties of the Oral Mucosa 330
23.2. Geno- and Phenotypic Characteristics of Oral Mucosal Fibroblasts 331
23.3. Oral Mucosa Progenitor Cells 331
23.3.1. Characterization of Oral Mucosa Lamina Propria Progenitor Cells 331
23.3.2. Oral Progenitors as a Source of iPSCs 333
23.3.3. Oral Mucosal Progenitors as Potent Immunosuppressive Cells 333
23.3.3.1. MSCs and the Immune System 333
23.3.3.2. Immunosuppressive Soluble Factors 333
23.3.3.3. The Immunomodulatory Potential of Oral Progenitors 333
23.4. Conclusion 336
Acknowledgments 337
Abbreviations 337
References 337
Chapter 24: Oral Mucosal Stem Cells: Identification, Characterization, and Clinical and Disease Implications 340
24.1. Introduction 340
24.2. Molecular and Phenotypic Markers for KSC Identification 341
24.2.1. Adult Hair Follicle KSC Markers 341
24.2.2. Epidermal KSC Markers 342
24.2.3. Corneal Limbal Stem Cell Markers 342
24.2.4. OKSC Markers 342
24.2.5. Enrichment of KSCs from Primary Tissue Specimens 342
24.3. Generation of Keratinocytes from Pluripotent Stem Cells 343
24.4. Molecular Pathways Regulating KSC Stemness 343
24.4.1. Notch Signaling Pathway 343
24.4.2. Wnt Signaling Pathway 343
24.4.3. TGF- ß /BMP Signaling Pathway 343
24.5. Epithelial Tissue Engineering Using OKSCs 344
24.5.1. Enhanced Regeneration Capacity of OKSCs 344
24.5.1.1. Wound Healing Example 344
24.5.2. Oral Mucosal Graft Transplantation 345
24.5.3. OKSC Scaffold Transplantation in Ocular Reconstruction 345
24.6. Control of Replication, Senescence, and Differentiation of Oral Keratinocytes 345
24.6.1. Intrinsic Model of Cellular Senescence 346
24.6.1.1. Dependence on Telomere Status 346
24.6.2. Extrinsic Model of Senescence 346
24.6.2.1. Dependence on Environmental Factors 346
24.6.3. Control of Keratinocyte Differentiation 347
24.6.3.1. Grainyhead-Like 2 Is the Master Regulator of Keratinocyte Proliferation and Differentiation 347
24.7. Mechanisms Involving Cellular Immortalization of Oral Mucosal Keratinocytes 349
24.8. Relevance of KSCS for Oral Carcinogenesis 349
Acknowledgments 351
Abbreviations 351
References 351
Chapter 25: Optimization of Stem Cell Expansion, Storage, and Distribution 356
25.1. Introduction 356
25.2. Key Concepts 356
25.3. Optimization of Stem Cell Expansion Processes 357
25.3.1. Recent Developments in Somatic Stem Cell Culture 357
25.3.1.1. Optimal Culture and Induction Protocols 357
25.3.1.2. Animal-Free Culture 357
25.3.1.3. Novel Culture Technologies 358
25.3.1.4. Automated Cell Culture Systems 359
25.3.2. Expansion of Bone Marrow Stromal Cells for Bone Tissue Engineering 360
25.3.2.1. Consideration of BMSCs Expansion for Bone Tissue Engineering 360
25.3.2.2. Safety Concerns of BMSCs in Clinical Application 360
25.3.3. Procedures for Seeding Cells onto Scaffolds 361
25.4. Development of Cell Storage Technologies 361
25.4.1. Cryopreservation of Cultured Cells 361
25.4.2. Novel Technological Developments in Cryopreservation 361
25.4.3. Considerations for the Cryopreservation of Tissue-Engineered Products 361
25.5. Distribution of Tissue-Engineered Products 362
25.5.1. Conditions Required for the Transportation of Tissue-Engineered Products 362
25.5.2. Effect of Transportation on Cell Viability 362
Acronyms and Abbreviations 362
References 362
Part V: Tooth Tissue Engineering 366
Chapter 26: Development of Tooth and Associated Structures 368
26.1. Odontogenesis 368
26.1.1. Epithelio-Mesenchymal Origin of Dental Tissues and Embryonic Development 368
26.1.2. Determination of Odontogenic Region and Tooth Identity 368
26.1.3. Antero-Posterior Patterning 369
26.1.4. Determination of Tooth Shape and Number 369
26.1.5. Morphogenesis 369
26.1.6. Terminal Differentiation and Mineralization 369
26.1.6.1. Dentinogenesis 370
26.1.6.2. Amelogenesis 370
26.1.6.3. Cementogenesis 371
26.2. Odontogenesis and Osteogenesis 372
26.2.1. Osteogenesis 372
26.2.2. Alveolar and Jaw Bone Development 372
26.2.3. Alveolar Bone: Extracellular Matrix 375
26.2.4. Root Development and Formation of Periodontium 375
26.2.5. Failures in Odontogenesis and/or Osteogenesis 377
References 379
Chapter 27: Dental Stem Cells for Tooth Tissue Engineering 380
27.1. Introduction 380
27.2. Embryonic and Postnatal Tooth Bud Cells 382
27.3. Dental Epithelial Progenitor/Stem Cell from the Enamel Organ 382
27.4. Epithelial Cell Rests of Malassez (ERM) 383
27.4.1. Dental Epithelial Stem Cells in the ERM 385
27.5. Dental Papilla Progenitor Cells 386
27.6. Dental Follicle Stem Cells 387
27.7. Dental Pulp Stem Cells 388
27.8. Conclusion 389
Acknowledgments 390
References 390
Chapter 28: Tooth Organ Engineering 392
28.1. Introduction 392
28.2. Tooth Organ Engineering Using Dental Embryonic Cells 392
28.2.1. Crown Morphogenesis, Epithelial Histogenesis, and Cell Differentiation 392
28.2.2. Root, Periodontium, and Bone Formation 394
28.2.2.1. Root Formation 394
28.2.2.2. Periodontium Attachment to Bone 395
28.2.3. Innervation 396
28.2.4. Fate of Engineered Teeth After Long-Term Implantation 398
28.3. Tooth Engineering Using Non-Dental Cells 398
28.3.1. Mesenchymal Cells 398
28.3.2. Epithelial Cells 398
28.4. Human Dental Stem Cells 399
28.5. Conclusion 399
Acknowledgments 399
References 399
Part VI: Tissue Engineering in Endodontics 402
Chapter 29: Biology of the Dentin-Pulp Complex 404
29.1. Introduction 404
29.2. Dentin Structure and its Biochemical Properties 404
29.2.1. Predentin 405
29.2.2. Mantle Dentin 405
29.2.3. Teritary Dentin 406
29.3. Components of the Dentin Extracellular Matrix 406
29.3.1. Collagen 406
29.3.2. Small Leucine-Rich Proteoglycans (SLRPs) 406
29.3.3. Small Integrin-Binding Ligand N-linked Glycoproteins (SIBLINGs) 407
29.4. Growth Factors and Cytokines within the Dentin ECM 407
29.5. The Dental Pulp 408
29.5.1. Biochemical Properties of the Pulp 408
29.5.2. Cellular Composition of the Pulp 409
29.5.2.1. Odontoblasts 409
29.5.2.2. Dental Pulp Stem/Progenitor Cells 409
29.5.3. Other Cells of the Pulp 410
29.5.4. Nerve Endings and Neurotransmitters 410
References 410
Chapter 30: Odontoblasts and Dentin Formation 412
30.1. Key Concepts 412
30.2. Odontoblast Life Cycle 413
30.2.1. From Neural Mesenchymal Cells to Aged Odontoblasts 413
30.2.2. Regulation of Odontoblast Terminal Differentiation 416
30.3. Primary and Secondary Dentinogenesis 417
30.3.1. Primary Dentinogenesis 417
30.3.1.1. Matrix Molecules Synthesis and Secretion 417
30.3.1.1.1. Collagens 418
30.3.1.1.2. Non-Collagenous Proteins 418
30.3.1.1.3. SIBLINGs 418
30.3.1.1.4. Other Non-Collagenous Proteins 419
30.3.1.1.5. Proteoglycans 419
30.3.1.1.6. Glycosaminoglycans 419
30.3.1.1.7. Matrix Metalloproteinases and Other Enzymes 419
30.3.1.2. Mineralization Process 419
30.3.2. Secondary Dentinogenesis 420
30.4. Tertiary Dentinogenesis 420
30.4.1. Reactionary Dentinogenesis 420
30.4.2. Reparative Dentinogenesis 421
30.5. Non-Dentinogenic Function of Odontoblasts 423
30.5.1. Odontoblasts in the Dental Pulp Immune and Inflammatory Response 423
30.5.2. Odontoblasts as Sensor Cells 424
30.6. Conclusion 425
Acknowledgment 425
Abbreviations 425
References 426
Chapter 31. Pulp Injury and Changing Trends in Treatment 430
31.1. Introduction 430
31.2. Biological Basis for Regeneration 430
31.3. Regeneration Versus Revascularization 433
31.4. Overview of Current Literature from A Tissue Engineering Perspective 433
31.5. Are we There Yet? Considerations of Current Clinical Protocols 434
Acknowledgment 434
References 434
Chapter 32: Cellular Signaling in Dentin Repair and Regeneration 438
32.1. Introduction 438
32.2. Microbial Signaling in Caries 438
32.3. Dentin-Derived Molecular Signals in Caries 440
32.4. Dentin-Pulp Signaling and the Inflammatory Response 441
32.5. Signaling in Tertiary Dentinogenesis 442
32.5.1. Reactionary and Reparative Dentinogenesis 442
32.5.2. Chemotactic Signaling of Stem/Progenitor Cell Recruitment 443
32.5.3. Signaling of Odontoblast-Like Cell Differentiation and Parallels with Tooth Development 444
32.5.4. Molecular Regulation of Odontoblast Secretory Activity 444
32.6. Angiogenic and Neurogenic Signaling During Repair and Regeneration 445
32.7. Cellular Signaling and Clinical Opportunities 445
References 446
Chapter 33: Tissue Engineering Strategies for Endodontic Regeneration 452
33.1. Introduction 452
33.2. Treatment of Dental Pulp Necrosis in Immature Teeth 452
33.3. Dental Pulp Tissue Engineering 454
33.3.1. Stem Cells in Dental Pulp Tissue Engineering 456
33.3.2. Morphogenic Signals in Dental Pulp Tissue Engineering 457
33.3.3. Injectable Scaffolds in Dental Pulp Tissue Engineering 458
33.4. Concluding Remarks 459
Abbreviations 460
References 460
Part VII: Periodontal Tissue Engineering 464
Chapter 34: Periodontium and Periodontal Disease 466
34.1. Introduction 466
34.2. Functional Anatomy of the Periodontal Tissues 467
34.2.1. Gingiva 467
34.2.2. Periodontal Ligament 468
34.2.3. Alveolar Bone 468
34.2.4. Cementum 469
34.2.5. Adaptive Changes to Occlusal Loading 469
34.3. Signs and Symptoms of Periodontal Diseases 470
34.3.1. Gingivitis 470
34.3.2. Periodontitis 470
34.3.3. Classification of Periodontal Diseases 471
34.4. Etiology of Periodontal Disease 472
34.4.1. Smoking 472
34.4.2. Genetic Factors 472
34.4.3. Systemic Diseases 473
34.4.4. Psychosocial Factors 473
34.5. Pathogenesis 473
34.5.1. Bacterial Factors 473
34.5.2. Host Responses 473
34.5.3. Mechanisms of Tissue Damage 474
34.6. Management of Periodontal Diseases 474
34.6.1. Treatment Outcomes 475
34.7. Conclusion 476
References 476
Chapter 35: Biological Aspects of Periodontal Disease 478
35.1. Introduction 478
35.2. Morphogenesis 479
35.2.1. Odontogenic Progenitors Originate from the Cranial Neural Crest 479
35.2.2. Cell Fate Decisions in the Dental Follicle: Establishing the Periodontal Tissues 480
35.2.3. The Role of Hertwig’s Epithelial Root Sheath in Tooth Root and Periodontal Development 482
35.2.4. Development and Maintenance of the Gingiva 482
35.3. Periodontal Wound Healing 484
35.3.1. Mechanisms of Wound Healing in the Periodontium 484
35.3.2. Morphogenesis and Wound Healing of the Periodontium: Parallels and Contrasts 486
35.4. Current and Future Wound Healing Strategies in the Periodontium 487
35.5. Conclusion 487
Abbreviations 487
References 488
Chapter 36: Periodontal Regeneration: Current Therapies 492
36.1. Introduction 492
36.2. Bone Grafts 493
36.2.1. Autografts 493
36.2.2. Allografts 494
36.2.3. Xenografts 494
36.2.4. Alloplastic Graft 494
36.3. Guided Tissue Regeneration (gtr) 495
36.4. Biologics 496
36.4.1. Platelet-Derived Growth Factor (PDGF) 497
36.4.2. Bone Morphogenetic Proteins (BMP) 497
36.4.3. Enamel Matrix Derivative (EMD) 498
36.4.4. Fibroblast Growth Factor-2 (FGF-2) 498
36.5. Recent Advances 498
36.5.1. Gene Therapy 498
36.5.2. Stem Cell Therapy 498
36.6. Summary and Conclusions 499
Acknowledgments 499
References 499
Chapter 37. Periodontal Tissue Engineering: Current Approaches and Future Therapies 504
37.1. Introduction 504
37.2. Periodontal Tissue Engineering 505
37.3. Stem Cells for Periodontal Tissue Engineering 505
37.3.1. Stem Cells of Dental Origin 505
37.3.1.1. Periodontal Ligament Stem Cells (PDLSCs) 505
37.3.1.2. Root Apical Papilla Stem Cells 507
37.3.1.3. Dental Follicle Stem Cells 507
37.3.1.4. Stem Cells from Pulp Tissue 507
37.3.2. Stem Cells of Non-Dental Origin 508
37.3.2.1. Bone Marrow-Derived Mesenchymal Stem Cells 508
37.3.2.2. Adipose-Derived Stem Cells 508
37.3.2.3. Embryonic Stem Cells/Induced Pluripotent Stem Cells 508
37.4. Cell Therapy for Periodontal Tissue Engineering 509
37.4.1. Cell Sheet for Periodontal Regeneration 509
37.4.2. Cell Pellet for Periodontal Regeneration 510
37.5. Gene Therapy for Periodontal Tissue Engineering 510
37.5.1. The Biology of Gene Therapy 511
37.5.2. Gene Therapy for Periodontal Regeneration 511
37.6. Conclusion 512
Acknowledgments 512
Acronyms and Abbreviations 512
References 513
Part VIII: Craniofacial Tissue Engineering 516
Chapter 38: Molecular Strategies in the Study and Repair of Palatal Defects 518
38.1. Introduction 518
38.2. Genetic and Environmental Influences 519
38.2.1. Linkage Studies 519
38.2.2. Association Studies 519
38.2.3. Genome-Wide Association Studies 519
38.3. Signal Transduction and Orofacial Development 520
38.3.1. Transforming Growth Factor ß 520
38.3.2. Sonic Hedgehog 521
38.3.3. Wnt Proteins 521
38.4. Tissue Engineering Strategies for the Repair of Palatal and Other Craniofacial Defects 522
38.4.1. Stem Cells 524
38.4.2. Scaffolds 524
38.4.3. Culture Systems 525
38.4.4. Enhancing Vascularization of Bioengineered Constructs 525
38.4.5. Manipulation of Gene Expression 526
38.4.6. Clinical Reports 526
38.5. Summary 527
Acknowledgments 527
Abbreviations 527
References 527
Chapter 39: Molecular Genetics and Biology of Craniofacial Craniosynostoses 532
39.1. Craniofacial Synostosis Overview 532
39.1.1. Normal Calvarial and Facial Anatomy, Histology, Definition of Synostosis 532
39.1.2. Normal Timing of Fusion of Craniofacial Sutures 533
39.1.3. Craniosynostosis 533
39.2. Molecular Genetics of Craniosynostosis 534
39.2.1. Syndromic Craniosynostosis 534
39.2.1.1. FGFRs 534
39.2.1.2. TWIST1 and RUNX2 536
39.2.1.3. EFNB1 536
39.2.1.4. TGFBR 536
39.2.1.5. Other Genes 536
39.2.2. Single Suture Synostosis 538
39.2.3. Transcriptomic Clues to the Cause of Single Suture Craniosynostosis 539
39.3. Impact of Craniosynostosis Mutations on Protein Structure and Function 539
39.3.1. Structural Analysis of Unique Craniosynostosis Variants 539
39.3.2. Understanding Domain Function through Dysfunction 541
39.4. Integration of Molecular Genetics and Suture Biology 544
39.4.1. The Regulation of Calvarial and Facial Suture Patency 544
39.4.2. Fgf Signaling Controls Osteoblast Proliferation in Craniofacial Sutures 546
39.4.3. Crosstalk with Other Signaling Pathways: the TGFbeta and BMP Pathways 547
39.4.4. Eph/ephrins: Roles in Osteoblast Communication and Boundary Formation 547
39.4.5. A Possible Role for Cilia in Suture Biology 547
39.4.6. Other Molecular Players 548
39.5. Targets for Stem Cell Therapies and Tissue Engineering Strategies in Craniofacial Disorders 548
References 549
Chapter 40: Tissue Engineering Craniofacial Bone Products 554
40.1. Introduction: The Need for Tissue-Engineered Bone Products 554
40.1.1. Key Concepts 555
40.2. Strategies for Tissue Engineering of Bone Substitutes 555
40.2.1. In Vivo Tissue Engineering 556
40.2.2. Ex Vivo Tissue Engineering 556
40.3. Components of Te Bone Products 556
40.3.1. Human Osteogenic Cells 556
40.3.1.1. Primary Osteoblasts from the Bone Tissue 557
40.3.1.2. Periosteum-Derived Mesenchymal Progenitors 557
40.3.1.3. Bone Marrow-Derived Stromal/Stem Cell Populations 557
40.3.1.4. Adipose Tissue-Derived Stromal/Stem Cell Populations 557
40.3.2. Biomaterial Scaffolds 557
40.3.3. Osteoinductive Signals 558
40.3.4. Technologies for Cell Processing and In Vitro Cultivation of Bone Substitutes 558
40.4. The Properties and Clinical Use of Te Bone Products 559
40.4.1. TE Bone Products Containing Osteoconductive Scaffolds with Osteoinductive Factors 562
40.4.2. Custom-Made TE Bone Substitutes Containing Viable Cells for the Treatment of Individual Patients 563
40.4.2.1. Periosteal Progenitor-Derived Bone Substitutes 563
40.4.2.2. Primary Osteoblast-Derived Bone Substitutes 564
40.4.2.3. Bone Marrow Stromal/Stem Cell-Derived Bone Substitutes 564
40.4.2.4. Adipose Tissue Stromal/Stem Cell-Derived Bone Substitutes 566
40.4.3. Commercial TE Bone Products Containing Viable Cells 566
40.4.3.1. Biotissue Technologies Periosteum-Derived Tissue-Engineered Bone (BioSeed-Oral Bone) 566
40.4.3.2. Osiris Therapeutics/NuVasive Adult Stem C ells on Allogeneic Bone Matrix (Osteocel) 567
40.4.3.3. Aastrom Biosciences Bone Marrow-Derived Cell Transplants (Tissue Repair Cells) 567
40.4.3.4. Mesoblast Mesenchymal Precursor Cells (NeoFuse) 568
40.5. Future Challenges in the Development and Application of Te Bone Products 568
40.6. Conclusion 568
Acronyms and Abbreviations 569
References 569
Chapter 41: Craniofacial Cartilage Tissue Engineering 574
41.1. Introduction 574
41.1.1. Key Concepts 575
41.2. Cartilage as a Tissue Source 575
41.3. Cell Expansion in Monolayer Culture 576
41.4. Three-Dimensional Culture Systems 577
41.5. Optimizing the Growth Environment 578
41.5.1. Growth Factor Stimulation 578
41.5.2. Cartilage Tissue Engineering with Human Serum 578
41.5.3. Dynamic Culture Systems 578
41.6. Stem Cells: An Alternative Cell Source 580
41.7. In Vivo Maturation of Tissue-Engineered Cartilage 581
41.8. Future Challenges 582
41.9. Conclusion 582
Abbreviations 582
References 582
Chapter 42: Tendon and Ligament Tissue Engineering 586
42.1. Introduction and current treatment 586
42.1.1. Ligament/Tendon in the Craniofacial Region 586
42.1.2. Anterior Cruciate Ligament and Posterior Cruciate Ligament 587
42.1.3. Supraspinatus Tendon 588
42.2. Tissue Engineering strategies 589
42.2.1. Cells 589
42.2.2. Soluble Factors 590
42.2.3. Scaffolds 590
42.2.3.1. Collagen 591
42.2.3.2. Hyaluronic Acid, Chitosan, and Alginate 591
42.2.3.3. Silk 591
42.2.3.4. Synthetic Materials 592
42.3. Mechanical signals 592
42.4. Gene transfer for ligament/tendon regeneration 593
42.5. Animal studies 593
42.6. Human trials 595
42.7. Conclusions 595
Abbreviations 595
References 596
Chapter 43: Soft Tissue Reconstruction: Skeletal Muscle Engineering 600
43.1. Introduction 600
43.2. Skeletal muscle 601
43.2.1. Gross Structure 601
43.2.2. Ultrastructure 602
43.2.3. Extracellular Matrix 602
43.2.4. Integration with Other Systems 602
43.2.5. Satellite Cells 603
43.3. Introduction to craniofacial growth, as well as common congenital and acquired craniofacial muscle abnormalities and ... 604
43.3.1. Craniofacial Growth 604
43.3.2. Congenital and Acquired Craniofacial Abnormalities and Injuries 605
43.3.2.1. Muscle Hypoplasia 605
43.3.2.2. The Importance of Muscle Function to the Temporomandibular Joint 605
43.3.2.3. Muscle Trauma 605
43.3.3. Current Craniofacial Reconstructive Techniques 606
43.3.4. The Promise of Regenerative Medicine (RM) and Tissue Engineering (TE) for Craniofacial Reconstruction 606
43.4. Engineering skeletal muscle 607
43.4.1. Isolation of Muscle Precursor Cells 607
43.4.2. Synthetic Scaffold 608
43.4.3. Biomimetic Scaffolds 609
43.4.3.1. Collagen Matrices 609
43.4.3.2. Fibrin Matrices 609
43.4.3.3. Composite Matrices 610
43.5. Advancing maturation and function of engineered skeletal muscle 610
43.5.1. Mechanical and Electrical Signals 610
43.5.2. Addition and Integration of Other Cell Types 611
43.5.2.1. Growth Factors and Extracellular Matrix Proteins 612
43.5.2.2. Hypoxia 613
43.6. Novel technologies for in vivo muscle regeneration, repair, and replacement 613
43.6.1. Technologies for VML Repair Using Scaffold-Only Approaches 613
43.6.2. Technologies for VML Repair Using Scaffold Plus Cells 613
43.6.3. Summary and Conclusions 619
43.7. Future clinical implications 619
43.7.1. The Technology Gap 619
43.7.2. Application to the Craniofacial Region 619
43.7.2.1. Potential First Clinical Application 619
43.8. Conclusions 620
Abbreviations 620
References 620
Chapter 44: Multi-Tissue Interface Bioengineering 626
44.1. Introduction 626
44.2. Monolithic Scaffold-Based Approaches 627
44.3. Scaffolds with Discrete Functional Regions 628
44.4. Tissue Engineering Technologies to Improve Current Surgical Techniques 631
44.5. Future Directions 631
44.6. Conclusion 632
References 632
Chapter 45: Soft Tissue Reconstruction: Adipose Tissue Engineering 636
45.1. Introduction 636
45.2. Anatomy and Function of Adipose Tissue 636
45.2.1. Composition and Anatomy 636
45.2.2. Physiologic Functions 637
45.2.3. Diseases of Craniofacial Soft Tissue: Parry-Romberg Syndrome 637
45.3. Current Approach to Soft Tissue Reconstruction in The Craniofacial Region 637
45.3.1. Synthetic Fillers 637
45.3.2. Autologous Tissue Transfer 637
45.3.3. Fat Grafting 637
45.4. Adipose Tissue Engineering: Biomaterials, Stem Cells, and the Era of Regenerative Medicine 638
45.4.1. Biomaterials 638
45.4.1.1. Synthetic Polymers 638
45.4.1.2. Natural Polymers 639
45.4.2. Cell Sources 639
45.4.2.1. Human Mesenchymal Stem Cells 639
45.4.2.2. Pluripotent Cells 639
45.4.3. Culture Methodology 640
45.5. Current Research 640
45.6. Ethics 640
45.7. Conclusion 640
References 640
Part IX: Bioengineering Organs in Head and Neck 644
Chapter 46: Salivary Gland Tissue Engineering and Repair 646
46.1. Introduction 646
46.2. Salivary Gland Structure and Function 646
46.2.1. Salivary Gland Physiology and Fluid Secretion 647
46.2.2. Protein Secretion 647
46.3. Salivary Gland Atrophy and Repair 647
46.3.1. Rationale for Tissue Replacement 648
46.3.2. Salivary Gland Repair 648
46.3.3. Innervation and Vascularization 650
46.4. Biomaterial Scaffolds 650
46.4.1. Synthetic and Biologically Derived Hydrogel Scaffolds 650
46.4.2. Hyaluronic Acid-Based Hydrogels 651
46.4.3. Hyaluronic Acid-Based Hydrogel Particles 651
46.5. Recent Advances in Salivary Gland Tissue Engineering 652
46.5.1. Differentiation of Salivary Gland Cells 652
46.5.2. Branching Morphogenesis 652
46.6. Conclusion and Future Work 653
Acknowledgment 654
Abbreviations 654
References 654
Chapter 47: Tissue Engineering of Larynx 658
47.1. Introduction 658
47.1.1. Key Concepts 659
47.2. Laryngeal Anatomy 659
47.2.1. General Structure 659
47.2.2. Vocal Fold Structure and Function 659
47.2.2.1. Layers of the Vocal Fold Lamina Propria 660
47.2.3. Lamina Propria Extracellular Matrix 661
47.2.3.1. Fibrous Proteins 662
47.2.3.2. Interstitial Elements 663
47.3. Vocal Fold Microstructure Restoration 664
47.3.1. Scaffolds 664
47.3.1.1. Hyaluronic Acid Derivatives 665
47.3.1.2. Hydrogels 665
47.3.1.3. Microgels 665
47.3.1.4. 2,3-Dialdehydecellulose Membranes 665
47.3.1.5. Decellularized Xenogeneic ECM 666
47.3.1.6. Synthetic Elastomers 666
47.3.2. Cell Transplantation 666
47.3.2.1. Fibroblasts 666
47.3.2.2. Stem Cells 667
47.3.2.2.1. Human Embryonic Stem Cells 667
47.3.2.2.2. Bone Marrow-Derived Mesenchymal Stem Cells 667
47.3.2.2.3. Adipose-Derived Mesenchymal Stem Cells 667
47.3.3. Bioactive Factors 667
47.3.3.1. Basic Fibroblast Growth Factor 667
47.3.3.2. Hepatocyte Growth Factor 667
47.3.4. Mechanotransduction 668
47.4. Larynx Superstructure Bioengineering 668
47.4.1. Cartilage Regeneration 668
47.4.1.1. Tissue-Engineered Cartilage 668
47.4.1.2. Polypropylene Mesh Grafts 668
47.4.2. Decellularized Human Larynx 669
47.5. Neuromuscular Regeneration 669
47.5.1. Neurotrophic Factors 670
47.5.2. Artificial Nerve Conduits 670
47.5.3. Muscle Regeneration 670
47.6. Conclusion 671
Abbreviations 671
References 671
Chapter 48: The Bio-Artificial Trachea 674
48.1. Introduction 674
48.1.1. Tracheal Pathology: The Clinical Need 675
48.1.2. Tissue-Engineered Trachea: The Concept 675
48.2. In Vitro Scaffold Assessment for Trachea Tissue Engineering 676
48.3. In Vivo Scaffold Assessment for Trachea Tissue Engineering 678
48.4. Tissue Engineering The Trachea 680
48.5. Conclusion 682
Acronyms and Abbreviations 683
References 683
Chapter 49: Tissue Engineering of the Esophagus 686
49.1. Introduction 686
49.2. Anatomy, Histology, and Physiology 686
49.2.1. Histology 686
49.2.2. Physiology 687
49.2.3. Potential Clinical Indications 687
49.2.3.1. Barrett’s Esophagus (BE) 687
49.2.3.2. Esophageal Cancer 687
49.2.3.3. Esophageal Atresia (EA) 687
49.2.3.4. Trauma 688
49.2.3.5. Alkali and Acid Ingestion 688
49.2.4. Surgical Therapy 688
49.3. Tissue Engineering 688
49.3.1. Cell Sources 689
49.3.2. Scaffolds 690
49.3.2.1. Esophagus Extracellular Matrix Scaffolds 690
49.3.2.2. Extracellular Matrix Derived from Other Organs 691
49.3.3. Artificial Scaffolds 693
49.3.4. Clinical Trials 695
49.4. Conclusion 695
Acronyms and Abbreviations 696
References 696
Part X: Tissue Engineering Skin and Oral Mucosa 700
Chapter 50: Cell and Molecular Biology of Wound Healing 702
50.1. Introduction 702
50.2. Evolutionary Perspective to Mucosal and Skin Wound Healing 703
50.3. Inflammation and Wound Healing 704
50.3.1. Platelets Initiate Wound Healing 704
50.3.2. Neutrophils Dictate the Onset and Resolution of Inflammation in Wounds 704
50.3.3. Macrophages: Important Modulators of Wound Healing 706
50.4. Re-Epithelialization of Wounds 708
50.4.1. The Process of Re-Epithelialization 708
50.4.2. Activation and Mobilization of Wound Edge Keratinocytes 708
50.4.3. Active Re-Epithelialization 709
50.4.4. Final Stages of Re-Epithelialization 711
50.5. Connective Tissue Wound Healing: Granulation Tissue Formation and Remodeling 711
50.5.1. General Overview 711
50.5.2. Origin of Connective Tissue Cells that Heal the Wounds 711
50.5.3. Cell Activation: Initial Step in Connective Tissue Wound Healing 713
50.5.4. Cell Migration into the Wound Provisional Matrix 713
50.5.5. Myofibroblasts Produce the Granulation Tissue Matrix and Remodel it 713
50.5.6. Angiogenesis 715
50.5.7. Remodeling Stage of Wound Healing 717
50.5.8. Excessive Scar Formation and Fibrosis 718
50.6. Conclusions 719
Acknowledgments 720
Abbreviations 720
References 720
Chapter 51: Models of Differential Wound Healing 724
51.1. Introduction 724
51.2. Cutaneous Wound Healing (Adult Vs. Fetal) 726
51.2.1. Inflammatory Response 726
51.2.1.1. Inflammatory Cells 726
51.2.1.2. Inflammatory Cytokines 726
51.2.2. Extracellular Matrix (ECM) 727
51.2.2.1. Fibroblasts 727
51.2.2.2. Collagen 727
51.2.2.3. Other ECM Proteins and Modulators 728
51.3. Oral Mucosa 729
51.3.1. Inflammatory Response 729
51.3.1.1. Inflammatory Cells 729
51.3.1.2. Inflammatory Cytokines 729
51.3.2. Saliva 730
51.3.3. Extracellular Matrix 730
51.3.3.1. Fibroblast 730
51.3.3.2. Collagen and Other ECM Molecules 731
51.4. Summary 732
References 732
Chapter 52: Bioengineering Skin Constructs 736
52.1. Introduction 736
52.2. Traditional Treatments for Skin Injuries 737
52.2.1. Autograft 737
52.2.2. Allograft 737
52.2.3. Wound Dressing 738
52.3. Tissue Engineering Approach for Skin Repair 738
52.3.1. The Need for Tissue-Engineered Skin Substitutes 738
52.3.2. The Key Factors of Tissue-Engineered Skin 738
52.3.2.1. Scaffolds 738
52.3.2.2. Cells 740
52.3.2.3. Bioactive Factors 741
52.4. Current Progress 742
52.4.1. Tissue-Engineered Epidermis 742
52.4.2. Tissue-Engineered Dermis 742
52.4.3. Tissue-Engineered Skin 744
52.5. Important Challenges and Strategies 745
52.5.1. Angiogenesis 745
52.5.2. Scarring 746
52.5.3. Appendages 747
52.6. Conclusions and Future Perspectives 749
References 749
Chapter 53: Three-Dimensional Reconstruction of Oral Mucosa: Tissue Engineering Strategies 754
53.1. Introduction 754
53.2. Conventional treatment for reconstruction of oral mucosa defects 754
53.3. Goals of oral mucosa Tissue Engineering 755
53.4. Strategies for Tissue Engineering of oral mucosa 755
53.4.1. Epithelial Sheets 755
53.4.2. Dermal Substitutes 756
53.4.3. Bi-Layered 756
53.5. Pre-clinical and clinical studies on teoms for intraoral and extraoral applications 757
53.5.1. In Vivo Animal Studies 757
53.5.2. Human Clinical Application (Intraoral Grafting) 757
53.5.3. Pre-Clinical and Clinical Applications (Extraoral Grafting) 757
53.6. Regulatory issues of tissue-engineered product manufacturing 759
53.7. Challenges 759
53.8. Future strategies 759
53.9. Conclusions 760
References 761
Part XI: Tissue Engineered Implant Dentistry 766
Chapter 54: Dental Implantology and Implants: Basic Aspects and Tissue Interface 768
54.1. Introduction 768
54.2. History and readers 768
54.3. Anatomy of dental implants and clinical aspects 769
54.4. “Stem cells” and Tissue Engineering in implant dentistry 770
54.5. Tooth versus dental implant 770
54.6. Biological principles of hard and soft tissue integration 772
54.7. Surface modifications of titanium implants 773
54.8. Implant failures 774
54.9. Alternative materials 775
54.10. Future aspects 775
References 776
Chapter 55: Dental Implant-Guided Bone Tissue Engineering 782
55.1. Introduction: Key Concepts 782
55.2. Dental Implants 783
55.3. Alveolar Ridge Bone Loss: the Clinical Problem 784
55.4. Current Approaches for Alveolar Ridge Augmentation 784
55.4.1. Onlay Block Grafts 784
55.4.2. Guided Bone Regeneration (GBR) 784
55.4.3. Distraction Osteogenesis (DO) 784
55.5. The Concept of Implant-Guided Alveolar Ridge Bone Tissue Engineering 785
55.6. Animal Models and Pre-Clinical Testing Results for Implant-Guided Bone Tissue Engineering 785
55.6.1. The Development of a Murine Calvarial Dental Implant Model 786
55.6.2. The Development of a Rat Extraoral Mandible Model 786
55.6.3. The Development of a Rabbit Extraoral Mandible Model 788
55.6.4. Dog Intraoral Model 789
55.6.5. Minipig Intraoral Model 789
55.7. Bioactive Osteogenic Molecules for Use in Alveolar Ridge Augmentation 789
55.8. Delivery of Osteogenic Molecules from Dental Implants and Scaffolds 791
55.8.1. Titanium Implants for Delivery of Osteogenic Agents 791
55.8.2. Calcium Phosphate Biomaterials 791
55.8.3. Hydroxyapatite Coated Collagen Scaffold 792
55.8.4. Polyethylene Glycol Hydrogel Scaffold 792
55.8.5. Demineralized Bone Matrix 792
55.9. Cell-Based Alveolar Ridge Augmentation Approaches 792
55.10. Conclusions 793
References 794
Chapter 56: Periodontal Tissue Engineering Around Dental Implants 798
56.1. Introduction 798
56.2. PDL Development 798
56.2.1. Embryogenesis of PDL Attachment 798
56.2.2. Osseointegration Versus PDL Integration 799
56.3. Tissue Engineering PDL Tissues 799
56.3.1. Growth Factors 800
56.3.2. Stem Cells in PDL Tissue Engineering 800
56.3.3. Scaffolds in PDL Tissue Engineering 801
56.3.4. Titanium Surface and PDL Regeneration 801
56.4. Review of Literature 802
56.5. Conclusion 805
References 805
Part XII: Tissue Engineering in Orthodontics & Dentofacial Orthopedics
Chapter 57: Biological and Molecular Mediators During Orthodontic Tooth Movement 810
57.1. Introduction 810
57.1.1. Key Concepts 810
57.2. Molecular Activities During OTM 811
57.2.1. Early Phases of OTM 811
57.2.1.1. Extracellular Matrix 812
57.2.1.2. Osteocytes 812
57.2.1.3. Periodontal Fibroblasts 813
57.2.1.4. Inflammation 813
57.2.2. Later Phases of OTM 814
57.2.2.1. Bone Resorption (Osteoclasts) 814
57.2.2.2. Bone Formation (Osteoblasts) 815
57.2.3. Role of Prostaglandins during OTM 815
57.3. Challenges and Future Directions 816
57.4. Conclusion 817
Acknowledgment 817
References 817
Chapter 58: Accelerated Tooth Movement 820
58.1. Introduction 820
58.2. Orthodontic Tooth Movement (OTM) and Inflammatory Markers 821
58.3. Inflammatory Markers as a Method of Increasing the Rate of Tooth Movement 823
58.4. Physical Stimulation as a Method of Increasing the Rate of Tooth Movement 826
58.4.1. Mechanical Stimulation to Increase the Rate of Tooth Movement 826
58.4.2. Heat, Light, Electric Currents, and Laser to Increase the Rate of Tooth Movement 827
58.5. Chemical Agents to Increase the Rate of Tooth Movement 827
58.6. Summary and Future Directions 828
Abbreviations 828
References 828
Chapter 59: Stem Cell Therapy for Orthodontists: A Conceptual Introduction 832
59.1. Introduction 832
59.1.1. New Ideas and the Nature of Social Change 833
59.1.2. “NewThink” for a New Century 833
59.2. Tissue Engineering: A Relevant Science in Orthodontics 833
59.2.1. Orthodontic Tissue Engineering (OTE) 834
59.2.2. Bone Stem Cell Grafting Principles 834
59.3. Tissue Engineering: Recent Clinical Background 835
59.4. To Extract or not to Extract 836
59.4.1. Stem Cell Basics 838
59.4.2. Classification of Mesenchymal Stem Cells 839
59.5. Cluster Identification, Pharmaco-orthodontics, and Genetic Manipulation 840
59.5.1. Tissue Engineering Constructs and Scaffolds 840
59.5.2. Clinical Characteristics and Sources of Stem Cells 841
59.5.3. Extra Oral Sources of Stem Cells 841
59.5.4. Clinical Applications of Stem Cells and Bone Progenitor Cells 842
59.5.4.1. Autogenous Stem Cell Targeting 842
59.5.4.2. Allografts: Same Species, Different Individuals 843
59.5.4.3. Culture-Expanded Autogenous Grafts 843
59.5.4.4. Genetically Modified Stem Cell Grafts 843
59.5.4.5. Ex Vivo Tissue Generation and Transplantation 843
59.6. Challenges/Considerations in ORTHODONTIC Tissue Engineering 844
59.6.1. The Infection Challenge 844
59.6.2. Mass Transport and Diffusion Distance 845
59.7. Mechanobiology and the Peri-Orthodontic Hypothesis: Ote as Applied Molecular Biology 845
59.8. Beyond the Ligament: A New Perspective on Bone Behavior 847
59.8.1. Molecular Mechanisms 847
59.8.2. Bending Bone Bends DNA 848
59.9. Future Strategies 849
59.10. Epilogue as Prologue 850
Dedication 851
Acknowledgments 851
References 851
Chapter 60: Ultrasound Applications in Orthodontics 856
60.1. Introduction 856
60.2. Orthodontics and Stem Cells 857
60.3. Applications of Ultrasound in Medicine and Biology 858
60.3.1. Therapeutic Low-Intensity Pulsed Ultrasound (LIPUS) 858
60.3.2. Future Applications of Lipus in Orthodontics 859
60.4. Conclusions 859
References 860
Part XIII: Transplantation of Engineered Tissue Constructs 862
Chapter 61: Immunotherapy in Transplantation 864
61.1. Introduction 864
61.2. Immunomodulation Properties of Mesenchymal Stem Cells 864
61.2.1. Mesenchymal Stem Cells and Immune Cells 864
61.2.1.1. Interaction with T-Lymphocytes 865
61.2.1.2. Interaction with B-Lymphocytes 865
61.2.1.3. Interaction with Natural killer (NK) Cells 865
61.2.1.4. Interaction with Dendritic Cells (DCs) 865
61.2.1.5. Interaction with Regulatory T-Cells (Tregs) and T-Helper 17 Cells (Th17) 866
61.2.2. Pre-Clinical and Clinical Application of Mesenchymal Stem Cell Transplantation 866
61.3. Immunomodulation Properties of Mesenchymal Stem Cells in Dentistry 867
61.3.1. Mesenchymal Stem Cell from Jaw Bone Marrow 867
61.3.2. Dental Pulp Stem Cells 868
61.3.3. Periodontal Ligament Stem Cells 868
61.3.4. Stem Cells from Apical Papilla 868
61.3.5. Gingival Mesenchymal Stem Cells 868
61.4. Conclusion and Future Aspects 869
References 870
Chapter 62: Non-Invasive In Vivo Imaging of Transplanted Cells and Biomaterials 874
62.1. Introduction 874
62.1.1. Key Concepts 875
62.2. Diagnostic Imaging in Dentistry 875
62.3. The Challenge of Non-Invasive Imaging in Regenerative Dentistry 877
62.4. Approaches to Non-Invasively Visualize Implanted Cells 877
62.5. Visualizing Cells in the Context of Tissue Engineering/Regenerative Medicine 879
62.6. Conclusion 881
Acronyms and Abbreviations 881
References 881
Part XIV: Research Ethics and Law 886
Chapter 63: Ethics and Emerging Laws in Stem Cell Science 888
63.1. Introduction 888
63.2. Early Responses from Philosophical Ethics 888
63.2.1. Some Religious Viewpoints 889
63.2.2. Some Situated Ethical Viewpoints 890
63.3. Some Early Regulatory Responses to Human Embryonic Stem Cells 890
63.3.1. United States of America: Early Response 890
63.3.2. United Kingdom 891
63.3.3. Spain 891
63.3.4. Japan 892
63.3.5. India 892
63.3.6. Elsewhere 892
63.4. The Emergence of Somatic Cell Nuclear Transfer and the Demand for Ova 892
63.5. Forgotten Fetuses 893
63.6. Interspecies Embryos 893
63.7. The Fall of Professor Hwang Woo-Suk 894
63.8. The Arrival of Induced Pluripotency Stem Cells 894
63.9. Ongoing Issues 894
63.10. Conclusion 895
Acknowledgments 896
Acronyms and Abbreviations 896
References 896
Chapter 64: Ethical Aspects of Tissue Engineered Products 898
64.1. Introduction 898
64.2. Ethical Challenges in Cell Based Therapies 898
64.2.1. Fetal Cells 898
64.2.2. Private Banking of Cells 899
64.3. Safety 899
64.4. Informed Consent 900
64.5. Clinical Trials of TE Products 901
64.6. Intellectual Property Protection 901
64.6.1. International Laws 901
64.7. Discussion 902
Abbreviation 902
References 903
Chapter 65: Problems and Pitfalls in Tissue-Engineered Therapy 904
65.1. Introduction 904
65.2. “Classic” Development Pathway 904
65.3. Real World Examples 905
65.3.1. Apligraf 905
65.3.2. Dermagraft 905
65.3.3. INTEGRA® Dermal Regeneration Template (IDRT) 906
65.3.4. Epicel 907
65.4. Lessons and Conclusion 907
Acknowledgment 908
Glossary 910
Nomenclature 916
Index 922